code: def angle_between_vectors(p1, p2):
      x1, y1 = p1
      x2, y2 = p2
      theta = atan2(y2 - y1, x2 - x1)
      return theta
  
file_path: pygraphistry/graphistry/layout/utils/geometry.py
imports: from numpy import array, cos, sin
  from math import atan2, sqrt
label_desc: Use image node_id 3 for calling a global function with example usage: angle_between_vectors(p1, p2) and returns: theta